I make it a point to have 5-10 minute ad-hoc conversations with my directs 1-2 times a week, feels a lot more natural than a scheduled 1-on-1. Twice a year we have a company-sanctioned formal sit-down about perf.
As a result, people pop in my office regularly to start these conversations, which I prefer because it leads me to believe I am approachable, which is by far one of the most important things a manager should be.